Atari Punk Console debug

McGhie · August 26, 2008, 05:47:48 PM

Hey.. I decided to build an Atari Punk Console in a recycled Ikea-lamp. On perf. Complete nightmare, worst decision ever. Never touching perf again. Period.

Anywho, I went over to vero because it seemed much easier, and everyone seemed to be rather joyful of Dragonfly's vero layout. So I thought, well, if I just replace the jack with a speaker, it will probably work. Well, naïve as I may be, this is what I've done, and NO sound is coming through to the speaker.. And I thought, you guys are a mindblowingly sharp lot, so I thought that then maybe some of you would take the time to help me out here!
So here's how it's wired, exactly:

Thanks,
Thomas McGhie.

MusicAudio · August 26, 2008, 06:29:07 PM

Have you tried the circuit with just an output jack instead of the speaker?

I bet the 555 isn't too happy with having to drive such a low impedance.

oldrocker · August 26, 2008, 09:58:36 PM

If I'm not mistaken I believe the APC needs amplification of some kind to be audible. The output jack needs to plug into a Ruby or other amp to be heard.

McGhie · August 27, 2008, 03:26:18 PM

I forgot to add, the speaker is a small (4x4 cm) 8 ohm speaker.

It needs amplification?
I found a site where some guy had built one with an internal 8 ohm speaker, and someone posed the question as to whether id needed amplification. The guy in question answered that in his opinion, it did plenty of volume with just an internal speaker. Sorry, I can't find the link..

Also, wasn't the orinal circuit intended to drive a small 8 ohm speaker? And the Kaustic Machines shcem just swapped it for a -4 decibel line out? (What the hell is -4 decibels anyway?)

Maybe I'll try a line out this evening..

demonstar · August 27, 2008, 03:32:03 PM

If it does turn out to be a little amp you need at the end just use a little LM386 circuit to give you the 'umph' to drive the speaker.

McGhie · August 27, 2008, 04:01:34 PM

Quote from: demonstar on August 27, 2008, 03:32:03 PM
If it does turn out to be a little amp you need at the end just use a little LM386 circuit to give you the 'umph' to drive the speaker.

Cheers! Any tips on how to do a REALLY simple version of this? Preferably on veroboard..

dano12 · August 27, 2008, 04:15:44 PM

Quote from: McGhie on August 27, 2008, 04:01:34 PM
Quote from: demonstar on August 27, 2008, 03:32:03 PM
If it does turn out to be a little amp you need at the end just use a little LM386 circuit to give you the 'umph' to drive the speaker.

Cheers! Any tips on how to do a REALLY simple version of this? Preferably on veroboard..

It doesn't get any simpler than the smokey: two caps and a 386.

McGhie · August 27, 2008, 04:57:36 PM

Guys! It works! Well, sort of.. I still need help!

First of all, the line out WORKED, thanks guys! It now makes sound!
But here's the problem(s)..

It has a REALLY low volume, overpowered by hum, except when I touch one side of the pitch pot with my finger. On the plastic side, that is! You know, the (black) little square of plastic supporting the lugs of (some) pots. Plastic isn't supposed to conduct, is it?! But anyway, then the volume goes nice and loud. And I like it nice and loud.. any ideas?

Secondly, I think I accidentally used a really low value pot for the other pot. It switches between just two sounds when turned fully one way/ back again. I'll try a 1 m pot instead, shall I?

Cardboard Tube Samurai · August 27, 2008, 05:05:19 PM

Sounds like an earthing problem again

McGhie · August 27, 2008, 05:07:43 PM

Quote from: Cardboard Tube Samurai on August 27, 2008, 05:05:19 PM
Sounds like an earthing problem again

But what do I do? Solder the plastic to ground?!

McGhie · August 27, 2008, 05:21:24 PM

Just switched the pot that didn't really respond except for the two sounds with a 1 m pot.. exact same sound(s) as before..

McGhie · August 28, 2008, 02:46:17 AM

bumpity bump

demonstar · August 28, 2008, 04:43:25 AM

Everyone runs a mile when anyone mentions ground problems!

demonstar · August 28, 2008, 05:01:25 AM

I've been thinking and did you connect the grounds of the LM386 based amp to grounds of the ATC? If not that may be your problem.

McGhie · August 28, 2008, 05:35:00 AM

Quote from: demonstar on August 28, 2008, 04:43:25 AM
Everyone runs a mile when anyone mentions ground problems!

Stop running, damnit!

Quote from: demonstar on August 28, 2008, 05:01:25 AM
I've been thinking and did you connect the grounds of the LM386 based amp to grounds of the ATC? If not that may be your problem.

I ended up not installing the mini-amp, and put the line out in there instead.

Anyone, this must be something really simple..?

Cardboard Tube Samurai · August 28, 2008, 08:32:00 AM

Pics really help

McGhie · August 28, 2008, 08:53:16 AM

Quote from: Cardboard Tube Samurai on August 28, 2008, 08:32:00 AM
Pics really help

I will upload some later today!

McGhie · August 28, 2008, 06:09:05 PM

Ok, guys, prepare for one of the LONG posts!
(Photos, duh..)

The whole project, in an Ikea lamp. Just above the on/off switch are now two screws, they act as those.. touch-to-make-contact-and-have-fun-disco'ing-your-finger-around things. They connect a 22 uf cap between lug 2 and 5 on the 556.

INNARDS! Help yourself.

And here we have the uhm.. ground. Not the prettiest sight (it gets uglier,) but everything is connected, or so my DMM says..
Keep an eye on the blue wire and read/look on!

The blue wire and the bottom right wire on the layout goes to these screws inside the bottom of the lamp.

The current then goes through these height-adjustable legs... ( if I touch them, the sound is terminated while I do so..)

..and to the "head", where the bulb used to be, I reverse-attached the metal bowl/thing, and...

..here you can see a new set of screws, leading the current into the shielded wires, which are attached to the output jack.

Now to the problem!

Here you see the pot that only goes really audiable when I touch the right side of the black plastic in the second picture, or the right lug in the second picture..

here you have the circuit board, everything is connected as it should be, as far as I can see. The bottom left corner is the TOP left corner on the layout here, just in case you feel like comparing. The two wires (green and black) go to the 22 uf cap bend.

And finally, the other pot. The pulse-shaper or what you will, it sounds like it changes the length of the pulse if you listen closely, sort of like a REALLY subtle phaser, and it changes pitch a little when turned far left, but otherwise it does bollocks..

Everything is connected properly as far as I can read with my DMM, but feel free to make me re-measure anywhere you suspect might be doing evil!

Thanks again, hope you can make something out from the pictures!
/ Thomas McGhie

McGhie · August 31, 2008, 07:05:39 AM

Bump...?

McGhie · September 02, 2008, 03:15:09 PM

Please guys, I've checked every connection I could think of. I know the ground and pots don't look overall professional, but I'm a beginner, I'm learning. Also by trying to find out what is wrong with my APC, but I just can't figure it out. Any of you guys care to give me a hand on this one, besides what has already been suggested (and done and checked and doublechecked)?

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Atari Punk Console debug